Forensic Biology
Forensic biology is centered on the analysis of biological evidence, which is a type of evidence that is either a physical biological sample or a piece of evidence that may contain a biological material. Blood, for example, is a physical biological piece of evidence, while a cigarette butt would be an example of a piece of evidence that may contain biological material. In forensic biology, the matching of suspect and crime scene evidence is evaluated with instrumental data. Forensic serology, anthropology, pathology, and DNA analysis are all disciplines within forensic biology. Forensic serology is the study of bodily fluids, such as blood, saliva, semen, and sweat. Forensic anthropology involves the identification and analysis of skeletal remains, such as bones and teeth. Forensic pathology is the discipline in which medical examinations of human remains, or autopsies, occur.[1] DNA is the most common form of biological evidence, which may be recovered from a crime scene, assault victim, or deceased remains. DNA is frequently used to link a suspect to a crime scene. If the suspect’s DNA does not match the crime scene DNA, the suspect can be excluded, but if the DNA does correspond, then the suspect may have deposited the DNA at the scene.[2] Determining if an unknown DNA sample collected from the crime scene belongs to the suspect or the victim, requires the analyst to compare the instrumental profiles of DNA between the unknown sample and a potential person.
Refer to chapter 5 of the 2009 NAS report on forensic science for further description of types of biological evidence.[3]
Resources
- SWGDAM is the scientific working group for DNA analysis. It’s an excellent resource for documented procedures and standards for DNA analysis.
- NIST interlaboratory studies involving DNA mixtures (MIX05 and MIX13): Variation observed and lessons learned.
Reviews of Current Trends in Forensic Science
Forensic science is a constantly progressing field due to the advent of new instruments, techniques, and novel interpretations. Considering the evolving nature of the discipline, it is imperative that legal professionals and scientists remain aware of modern methods and advancements in forensic science. Emily Lennert with the UCF National Center for Forensic Science regularly reviews journal articles related to forensic science. Those reviews can be found here with the accompanying citation to the journal article for further reading.
Videos
DNA Basics – J. Christopher McKee, J.D.
DNA Issue Spotting – Steven K. Jacobson, J.D.
Forensic Serology: Body Fluid Identification – Phillip B. Danielson
DNA Bench Notes, Laboratory Documentation, and Learned Treatises – Nancy Peterson, B.S.
Basic Statistics – Nathan Adams, M.S.
The History of Forensic DNA Uses and Challenges – Dr. Dan E. Krane, Ph.D.
DNA Transfer and Contamination – J. Christopher McKee, J.D.
The Dawn of a New Era: Probabilistic Genotyping – Dr. Dan E. Krane, Ph.D.
Probabilistic Software and STRmix – Nathan Adams, M.S.
Admissibility Issue Spotting – Steven K. Jacobson, J.D.
Pretrial and Trial Strategies in DNA Cases – J. Christopher McKee, J.D.
Next Generation Detection Technologies in Forensic Science – Dr. Adam Hall
Biological Sex Determination Via Elemental Analysis by Laser-Induced Breakdown Spectroscopy – Dr. Mauro Martinez
[1] Forensic Pathology. http://www.nij.gov/topics/forensics/evidence/pathology/Pages/welcome.aspx (accessed July 14, 2016).
[2] DNA Evidence Basics. http://www.nij.gov/topics/forensics/evidence/dna/basics/pages/welcome.aspx (accessed July 14, 2016).
[3] Strengthening Forensic Science in the United States: A Path Forward; National Academies Press: Washington, D.C., 2009.